Mr. Adrian Harris is in the Chemistry lab at night, with the lights off, erasing the blackboard. He notices a scrap of paper on his desk, which has a number of Harrises on it, the last one being his name: Adrian R. Harris. He hears growling behind him and seems to know what's lurking. "Please don't kill me," he says. The alpha asks him who wrote the list of names, and he replies that it was Laura Hale. The alpha tells him that he knows why Laura wrote the list and orders Mr. Harris to turn around. He wants him to look at what he's done.
The alpha throws a chair when Adrian won't turn, and then Derek rushes into the lab and pushes him down to cover him. The alpha makes a run for it just as the police pull up to the school. Derek runs, and the cops follow. They chase him into the warehouse district. Sheriff Stilinski calls in that they're heading northwest. As Derek runs, he gets cut off by Chris Argent and slides to a stop to change directions. Chris reports to Kate that Derek is just under the ironworks. She's a bit stunned that he's running. "If he's on foot, then who the hell is driving his car?"
Scott looks in the rearview mirror and asks Stiles if he needs to drive faster. "Much faster," Stiles confirms.
The police release dogs after Derek. He turns and roars at them, and they give up the chase.
Stiles tells Scott that he doesn't think he's grasping the concept of a car chase. "If I go faster, I'll kill us!" "Well, if you don't go faster, they're gonna kill us!" But then suddenly Kate diverts. Stiles turns on the police scanner to hear that Derek is heading further into the ironworks.
Chris Argent shoots a flash bomb arrow near Derek, temporarily blinding him. Derek manages to hide behind a forklift, but Chris keeps shooting. Scott and Stiles pull up in the Camaro, and Derek dodges bullets to get in. Scott yells at Derek for not laying low. Derek yells back that he had the alpha right in front of him until the police showed up. "Well, hey, they're just doing their jobs," Stiles says, earning him a sharp look. Derek finally gripes about the fact that Scott made him the most wanted fugitive in the entire state. Scott apologies sort of and admits to making a dumbass mistake. Stiles tries to stop the shouting by asking Derek how he found the alpha.
Derek rolls his eyes, like he should trust telling them anything, and Scott asks him to trust them for half a second. "Both of us," Stiles adds, but when Derek glares at him, he decides to just sit in the back seat quietly. Derek tells them that the last time he talked to Laura she was close to figuring something out. She found two things: 1) a guy named Harris. Stiles leans forward, incredulous. "Our chemistry teacher?" But Derek doesn't know why Mr. Adrian Harris is important. The second thing she found was a symbol. Derek pulls out a sketch, and Scott recognizes it immediately as the Argent pendant that Allison has.
The next day at school, Scott and Stiles discuss how Scott is going to get Allison's necklace away from her. Stiles suggests talking to her and trying to ease back into a friendly relationship. "Get the necklace, get the alpha, get cured, get Allison back, in that order, got it?"
At the doctor's office, Jackson is getting his claw wounds examined. The doctor asks him what scratched him. Then he asks Jackson if he's been having trouble sleeping lately and whether he's had nightmares. Jackson tells him he's been having nightmares about a house on fire, and he can hear screaming. Apparently, Derek inadvertently shared his memories through his claws when he impaled Jackson's neck. Either that or the alpha is somehow projecting them. Jackson asks the doctor what dreams have to do with the wounds, and the doctor grabs a pair of foreceps, saying he needs to take a closer look. He comes at Jackson with a clawlike device, cutting into the wounds, and then starts extracting a long, gnarled strand of wolfsbane. Jackson screams and turns to see the doctor transformed into Derek.
Jackson blinks out of the hallucination to the doctor telling him he can put his shirt back on. His scabs are nothing to worry about. The doctor wants to give him antibiotics and tells him he has aconite poisoning. Aconite is another name for wolfsbane. On his way out of the hospital, Jackson stops by Melissa McCall's nurse station and asks her if he can use her computer. She replies that a handsome face like his probably doesn't hear no very often. He takes it as a compliment and smiles to himself. When she asks if he's one of Scott's friends, he tells her yes, and she lets him use her computer. Jackson hops on Inquiry-It and looks up wolfsbane, but we don't see what he finds.
At school, Jackson walks straight up to Scott and tells him he knows what he is. Scott tries to play dumb, but Jackson isn't buying it. He tells Scott that he wants to be a Werewolf, too. Scott will get him the Bite, or he's going to tell Allison.
Scott immediately tells Stiles that Jackson found out. Stiles asks if Jackson actually used the word, but Scott tells him the implication was pretty clear. Stiles suggests that maybe it isn't as bad as it seems because no one would believe him. Except, Scott points out, Allison's father. Stiles starts putting together a plan and asks where Derek is. Scott reminds him that it's their quarter finals game tonight and the first game Stiles will actually play in. Stiles tells Scott to just be sure he gets the necklace.
Lydia blocks Scott from sitting next to Allison in English class, so he sits slightly behind her. He asks her if he can send her some stuff on his phone that he thought she might like. He sends her photos of them together. They are learning about Iago from Othello and the way in which he preyed upon Othello's jealousy. Allison gets upset by the photos and leaves class. Scott runs after her. She asks him if he sent her the photos to try to make her feel even worse for breaking up with him. She tells him she needs more time to get to just friends and then walks away. Scott wanders back to class.
In the lunchroom, Stiles asks Scott about the necklace. Scott tells him what happened and admits that he knows nothing about girls. Stiles announces that he has a Plan B: just steal the stupid thing. Scott asks if they can try talking to Mr. Adrian Harris instead, but Stiles tells him he's under 24-hour protective detail. Just then Scott notices that Jackson is staring at them from across the room. Jackson then bites into an apple and watches curiously as Scott reacts to the sound. Then he tries talking to him without raising his voice. Scott tries to pretend that he can't hear him, but Stiles can tell something is wrong. Scott urges Stiles to talk to him like everything is normal so he won't have to listen to Jackson, but Stiles flails because his mind is a complete blank.
Jackson has disappeared from the lunchroom, but he keeps asking Scott what else he can do. Jackson taunts Scott about being a cheater at lacrosse, and Scott starts to get angry. Jackson again threatens to ruin any chance Scott has with Allison if he doesn't get the Bite. Then he tells him he's going to have sex with her. Scott gets so angry he breaks his lunch tray in half trying to hold it in. Jackson smirks at him from the corner of the lunchroom and crunches into his apple.
Jackson and Allison race in the swimming pool. He wins and tells her that he has an unfair advantage with his aerodynamically perfect cheekbones. Scott goes up into the bleachers around the pool and sits down near Allison's bag, trying to look nonchalant. He starts going through her things. Jackson asks Allison if she's coming to the game and insists that she does when she says no. He tells her that Scott wants her to be there and hoped that she wouldn't feel weird about it. Jackson flirts with her more and splashes her. Scott doesn't find the necklace.
Lydia approaches Jackson in the hallway and tells him that his text isn't funny. He agrees. He's breaking up with her. He asks for his spare house key back and tells her that he's decided to drop some of the dead weight in his life. She can't believe that she's been dumped.
Stiles hurries into his bedroom and straight for his computer. He doesn't notice Derek standing in the corner. Sheriff Stilinski calls from the hallway, and as Stiles turns to answer, he sees Derek standing there. Derek motions for him to answer his father, and Stiles flies toward the door to keep his dad from coming in the room. The Sheriff tells him that he's got some work to do but intends to see him play his first game. "I'm really happy for, and I'm very proud of you," Papa Stilinski says. They have an awkward conversation of smiles and hugs. The Sheriff keeps trying to decide what's wrong with his son but doesn't question it too much.
As soon as Stiles is back in his room, Derek shoves him up against the door and threatens him. Stiles tells him that if he's harboring his fugitive ass, it's his house and his rules. Derek sort of nods at him and lets him go, but not without a little aggressive exchange to make sure Stiles is still afraid of him. Derek asks about the necklace, and Stiles tells him that he's still trying to get it. He has another idea, though. The night at the school, Allison got a text telling her to meet them there. Stiles thinks they can trace the text back to the original sender.
Scott sneaks into Allison's room but isn't having any luck finding the necklace.
Danny is incredulous at Stiles's request that he trace a text. "I came here to do lab work." Danny wants to know why Stiles thinks he can do such a thing, and Stiles admits to looking up Danny's arrest report. "I was 13, they dropped the charges." He refuses to help, much to Stiles's annoyance. As Danny pulls up a chair to do lab work, he looks back at Derek, who is sitting in a chair next to Stiles's bed, reading. "Who is he again?" "My cousin. Miguel." This rather obvious lie likely gives Danny the impression that "Miguel" is actually Stiles' secret older boyfriend, especially given what happens next (something we see again later in 4x02 - 117),. Derek glances up at them but doesn't say anything. Danny asks if Miguel has blood on his shirt, and Stiles tells him that he gets horrible nose bleeds. "Hey, Miguel. I thought I told you you could borrow one of my shirts." Stiles gives Derek a look and motions him toward the dresser.
Derek scowls at him but gets up to do it. He strips off his bloody shirt, and Stiles starts telling Danny about how he knows he has the skills to do the trace. Derek interrupts to tell Stiles that the shirt "No fit." Stiles snarks at him to try something else on but then notices that Danny is staring at Derek. Derek puts one shirt on, and Stiles plays up asking Danny if it looks any good. Derek puts on his grumpiest face and waits. "It's not really his color," Danny says, and Derek strips that one off. "You swing for a different team, but you still play ball, don't you Danny boy," Stiles says. "You're a horrible person," Danny replies. Stiles pressures him again about the text, and Derek again tells him that none of the shirts fit while standing around shirtless.
Danny gives in.
Stiles is quite proud of himself.
Scott spots a receipt from the night at the bowling alley on Allison's desk. She wrote "First Date with Scott!!" on the back, and seeing it almost makes him cry. Then he notices a necklace chain inside a book on her desk and finds the pendant. The book is another telling of The Beast of Gevaudan. This one calls it a Loup garou. Scott translates on his phone to "Werewolf." Then he takes the pendant and leaves.
Derek manages to find a gray shirt that fits and stands over Danny and Stiles as Danny works. Danny tells them that the text was sent from a computer at the Beacon Hills Hospital registered to Melissa McCall.
Scott's just come down from the roof when Chris finds him. Chris welcomes him in and tells him that sometimes Allison goes for a run after school. Chris offers Scott a beer, and Scott tells him that he doesn't have to test him because Allison already dumped him. Scott still refuses the drink. Then Chris asks him how he knows Derek. Scott plays dumb.
Allison is out running in the Beacon Hills Preserve. She passes by the Hale House and decides to stop to take a closer look. She wanders through the house and finds claw marks on the floor. As she's looking at them, a figure approaches. Allison screams, but it turns out the figure is Kate. Kate followed her and asks her what she's looking for. Allison wants to know why Derek would want to kill her. Kate tells her to imagine how she'd feel if her family were trapped in a fire like this. "It wouldn't turn me into some psyschotic killer," Allison says. "You don't have to be psychotic to be a killer," Kate counters. "You just need a reason."
Kate asks Allison what she wants, and Allison replies that she wants to not be scared. Kate promises that with a little time and patience she can give her the feeling of power that she's looking for.
Chris has Scott sitting on the couch by the fire and he asks him again about Derek. Scott defends himself, asking why Chris is treating him like he's done something wrong. Chris sits down next to him and tells him that he doesn't have to be afraid of him, he's just thinking of Allison's safety. Scott replies that he thinks about that, too. Allison comes in and overhears them talking. Scott tells Chris that every choice he made in the school that night was to try to keep Allison safe. Chris tells him to go so he isn't late for his game.
Scott calls Stiles, who is in his Jeep with Derek. He tells him he got the necklace. Derek grabs Stiles's hand holding the phone and shouts into it asking if there's something on the back of the pendant. Scott insists that there's nothing in, on, or around it. Scott demands to know where Stiles is since he's first line. Coach Bobby Finstock comes over to Scott and asks the same thing. Scott says that he won't play if he's not there to start. Stiles smacks his hand on the steering wheel in frustration and asks Scott to just tell his dad he'll be a little late.
Derek looks at Stiles, clearly having overheard the whole conversation and surprised Stiles would give up something that means a lot to him and his dad in order to help Derek. "You're not going to make it." "I know." Derek also points out that he didn't mention Scott's mom and the text. Stiles insists they have to find out the truth. They are sitting outside the Beacon Hills Hospital Long Term Care facility. "By the way, one more thing?" Derek says. Then he slams Stiles's head into the steering wheel. As Stiles recoils, Derek tells him he knows what that was for: being used like a piece of meat with Danny. Then he orders Stiles to get moving.
Jackson sits down next to Scott and asks him if it's the Bite that does it. Scott confirms but tells Jackson that he can't do it. He tries to explain that being a Werewolf is a whole lot more trouble than Jackson thinks it is. Scott tells him about the hunters and looks at the Argents in the stand. Jackson makes the connection between "argent" and silver, which explains the myths about Werewolf being killed by silver.
Inside the hospital, Stiles is on the phone with Derek as he looks for Melissa. Derek tells him to ask for Jennifer, who has been looking after Peter Hale. "Yeah, well he's not here either," Stiles reports. Derek thinks for a second and then tells Stiles to get out of there. "It's him. He's the alpha. Get out!" Stiles turns and sees Peter standing there. "You must be Stiles," Peter says.
Stiles turns to run, but Nurse Jenny gets in his way. Stiles puts all the pieces together. "Oh my God, I'm gonna die," he says.
Then Derek arrives and elbows Jenny in the face, knocking her out. "That's not nice," Peter drawls. Derek tells Stiles to get out of the way, and Stiles just drops to the floor. Peter asks Derek if he thinks he killed Laura on purpose. Derek replies by attacking him. They throw each other against the walls while Stiles scrambles on the floor. Peter grabs Derek by the throat and drags him. "My mind, my personality, were literally burned out of me." He claims he killed Laura purely on instinct. Peter tells him that it was excrutiating healing so slowly and slowly coming back to consciousness. Killing Laura and becoming an alpha boosted his healing.
Peter tells Derek that he tried to warn him what was happening. He throws Derek through a glass wall, and Derek crawls along the ground to get away from him.
Sheriff Stilinski is interviewing Mr. Adrian Harris in the Chemistry lab. Still no lights on in there. Adrian says it was 6 years ago and before he had gotten sober. Mr. Adrian Harris tells him that he met a woman at a bar and they got drunk. The woman asked him about chemistry, and he was so thrilled to have someone who was interested in that talking to him that he answered everything she asked. How to dissolve a lock, how to dissolve a body and get away with murder. "How to start a fire and get away with arson?" the Sheriff asks. Mr. Adrian Harris nods and confirms that a week later the Hale House burned down. He didn't say anything because he didn't want to be an accomplice and have his career ruined. He says that the only thing he can tell him about who the woman was is a sketch of her pendant, the same thing he gave Laura Hale.
Peter paces after Derek as he crawls into a surgical room. Derek props himself against a wall, panting. Peter looks at himself in a mirror and then heals the still-burned half of his face. He tells Derek that he needs to give him a chance to explain himself.
Coach Finstock claps Jackson and Scott on the shoulder and gives them a pep talk. "No A in Econ if no win on field!" After he leaves, Jackson tells Scott that he's got 72 hours to get him turned into a Werewolf.
Sheriff Stilinski arrives at the stands and looks around for Stiles.
Kate and Allison talk about Jackson. Kate thinks he's hot and Allison should be all over him, until she sees the claw marks on Jackson's neck. Then she asks Chris if someone can be turned by a scratch. "If the claws go deep enough, maybe." She motions toward Jackson. Scott overhears the whole exchange.
When the lacrosse team breaks their huddle to start the game, Scott stands for a moment alone.